Difficulty: Easy
Write a function that takes an unsigned integer and returns the number of '1' bits it has(alse known as the Hamming weight).
For example, the 32-bit integer '11' has binary representation00000000000000000000000000001011, so the function should return 3.
class Solution(object):
def hammingWeight(self, n):
"""
:type n: int
:rtype: int
"""
weight = 0
while n > 0:
weight ++
n &= (n -1)
return weight